Restrictive Lung Disease USMLE Step 1 Practice Question
A 62-year-old man with a 40-pack-year smoking history presents with progressive dyspnea and a nonproductive cough over 8 months. He reports no occupational exposures, recent infections, or immunosuppressive medications. Vital signs show oxygen saturation of 88% on room air. High-resolution CT of the chest demonstrates bilateral lower lobe predominant reticular opacities with traction bronchiectasis and minimal ground-glass infiltrates. Pulmonary function tests reveal FVC 65% predicted, FEV1 62% predicted, FEV1/FVC ratio 0.78, and DLCO 45% predicted. Which of the following is the most likely diagnosis?
Answer choices
- AAcute interstitial pneumonia
- BNonspecific interstitial pneumonia
- CRespiratory bronchiolitis-associated interstitial lung disease
- DDesquamative interstitial pneumonia
- EUsual interstitial pneumoniaCorrect answer
- FLymphocytic interstitial pneumonia
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